The invention relates to apparatus for controlling the tension placed on a flexible tape, and more particularly relates to a vacuum column tension regulator for use in a tape cassette loader for controlling the tension applied to the magnetic tape during loading of tape into cassettes.
In the art of tape cassette loading, a predetermined length of tape is paid out from a spool and taken up and loaded within a tape cassette. Such cassette loaders include a single source of tension regulating the tension between the supply spool and the spool of the tape cassette. See for example U.S. Pat. No. 3,753,834 issued to James L. King on Aug. 21, 1973.
A vacuum column is an ideal tension regulating device for magnetic recording tapes or other flexible type tapes. Generally for a given vacuum column of a predetermined cross-sectional area, the quantity of vacuum pressure presented to the column determines the extent of tension placed on the tape. Thus, the vacuum pressure is regulated in order to regulate the extent of tension supplied by the column. However, where more than one vacuum column is utilized within a given tape path, a plurality of vacuum sources would be necessary in order to adjust each separate vacuum source to provide different tensions with respect to each vacuum column.
Therefore, it is highly desirable to provide a single vacuum source in which the vacuum tension is quickly and easily adjustable for providing a selected tension level, without the need to adjust the pressure of the vacuum supplied to the column.